The contractor shall participate as the clinical coordinating center for the randomized clinical trial of pharmacological and non-pharmacological treatments for Raynaud's syndrome. The primary goals of the study are to determine the best therapies for primary Raynaud's syndrome, particularly regarding the efficacy and duration of benefit from a course of temperature biofeedback treatment. Additionally, the study will evaluate the efficacy of the biofeedback approach in pre-sclerodermal Raynaud's, estimate the proportions of patients who have the primary and secondary form of the disorder, and establish new information with respect to the role of emotional reactivity in onset of symptoms. The information developed in this trial could be used to establish relative cost-effectiveness of pharmacological and non-pharmacological treatments. The study will consist of approximately 480 recruited participants from five participating clinical units. Prospective participants will undergo a medical evaluation to exclude patients with other conditions. Details of selection criteria, randomization procedures, treatment and assessment of treatment efficacy will be determined according to a final protocol developed by the Raynaud's Treatment Study steering committee, consisting of representatives from all entities participating in the study. Coordination of the final study design, data collection and its analysis will be conducted through this contractor.